JPH02249794A - Hydrofoil catamaran - Google Patents

Abstract

PURPOSE:To improve the stability for both rolling and lift force by providing in the lower of a deck part a pair of right and left barrel parts connected in their bottom parts by two or more hydrofoils arranged in a step differenced state providing a space mutually in the longitudinal direction further with a position displaced in the vertical direction. CONSTITUTION:A deck part 1 forms in its lower surface a pair of right and left barrel parts 2 in a shape narrowing a width in the lower side. The barrel part 2 provides in its bottom part a stepped part 4, equal to a width of that bottom part, protruding to the lower, and the stepped part 4 forms in its bottom part a tilt surface 7 with the front up further with curved surface shape. Hydrofoils 3A, 3B are arranged in a step differenced state displacing a position mutually in the vertical direction so as to connect the stepped parts 4 in right and left directions avoiding this tilt surface 7, and the hydrofoil is supported by a strut 6 in three points. By this constitution, rolling stability and lift stability in the hydrofoil part can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a twin-hulled hydrofoil boat, and particularly to a technique for preventing mutual interference between hydrofoil sections.

F Prior Art and Its Issues J Conventionally, while the ship is in operation, a hydrofoil is partially or completely submerged in water, and the buoyant force of the hydrofoil lifts the hull above the water surface. By lifting the ship, it reduces the water resistance that the hull receives, and enables high-speed operation by effectively utilizing the engine output.

In addition, because the hull is located far from the water surface, it is less affected by waves and is said to be able to reduce rocking during operation.

However, if multiple hydrofoils are spaced apart in the longitudinal direction and the spacing is small, or if the shapes of the front and rear hydrofoils are similar, the hydrofoil boat will not be able to operate at a high speed of, for example, 40 to 50 knots. When cavitation occurs between the front and rear hydrofoils, the air bubbles remain far behind, and the difference in resistance between areas with more air bubbles and areas with fewer air bubbles causes insufficient buoyancy. It becomes stable, and exercise performance is likely to be impaired.

In addition, if the height distance between the hydrofoil part and the bottom of the hull is close to each other in a type of boat such as a model in which the hydrofoil part is completely submerged in water, the hydrofoil part may be damaged when crossing waves. As parts of the body are exposed above the water, maneuverability is likely to be impaired.

The purpose of the present invention is to: 1) take advantage of the advantages of hydrofoils, 2) add stability against rolling that catamarans have, and 2) stabilize the buoyancy of the hydrofoil. That is.

"Means for Solving the Problems J" The present invention proposes three means for solving these problems.

The first means is that a pair of left and right body parts is provided at the bottom of the deck part, and hydrofoils with the bottom parts connected in the left and right direction are vertically attached to the bottom of the body parts at positions spaced apart in the front and back direction. It is a twin-hulled hydrofoil boat that is arranged in different directions with different positions.

The second means is a configuration in which a step portion having a front upwardly sloped surface is provided at the bottom of the pair of left and right body portions, and a plurality of hydrofoils are disposed at the bottom of the step portion. It is added to the means.

The third means is a configuration in which the dihedral angles of a plurality of hydrofoils are set differently depending on the front and back or top and bottom positions.
or in addition to the second means.

``Effect J When a catamaran hydrofoil in each of these methods is in a stopped state or in a state of low-speed operation, the pair of left and right hulls is submerged in water, resulting in stability against rolling similar to that of a catamaran. is obtained.

When a twin-hulled hydrofoil boat to which the first method is applied is put into operation, the buoyant force of the hydrofoils causes the hull to float up, and the deck part moves one inch above the water surface, making it less susceptible to the effects of waves. , the pair of left and right torso sections also levitate, reducing water resistance.

When these hulls float, the hydrofoil part is submerged in the water below the fuselage part to generate buoyancy, but because the hydrofoils are stepped, it is difficult to find the point where they intersect with the water. shifts vertically, suppressing the cavity john phenomenon and stabilizing the buoyancy force of multiple hydrofoils.

Furthermore, in the case of a twin-hulled hydrofoil boat to which the second means is applied, in addition to the effect of the first means, during operation, the buoyancy force due to the slope of the step part is added to the buoyancy force due to the hydrofoil. 6. Even if the pair of left and right fuselage sections floats up, the hydrofoils at the bottom of the step section remain submerged in the water. to stabilize the buoyancy force generated by the hydrofoil.

Furthermore, if it is a twin-hulled hydrofoil boat that applies the third method,
In addition to the effect of the first means or the second means, since the dihedral angle of the hydrofoil differs depending on the position, the occurrence of the cavity john phenomenon is suppressed by positional deviation based on the cross-sectional shape. action is added, and the cross-sectional shape where the hydrofoil intersects with the water is changed at each location 4
As a result, even if the cavity john phenomenon occurs locally, the hydrofoil becomes less susceptible to the effects and stabilizes the buoyancy force.

Embodiment J An embodiment of a twin-hulled hydrofoil according to the present invention will be described below with reference to FIGS. 1 to 4.

In the figure, 1 is a deck part (hull), 2 is a fuselage part, 3A to 3D are hydrofoils, 4 is a step part, 5 is a tunnel part, 6 is a wing support strut, 7 is an inclined surface, S is the support point.

As shown in FIG. 3, the lower surface of the deck portion (hull) 1 is set in a horizontal plane except for the trunk portions 2, and a pair of trunk portions 2 are provided at the lower portions on both left and right sides thereof.

As shown in Fig. 3, the pair of left and right body parts 2 are set in such a shape that the width of the lower side is narrowed, and a step part 4, which is equal to the width of this part, is provided at the bottom of the lower part. The step portion 4 is provided in a protruding state, and as shown in FIG.
Hydrofoils 3A and 3B, which are connected in the left-right direction, are provided so as to be shifted from each other.

In other words, as shown in FIGS. 1 to 3, the hydrofoils 3A and 3B are located at the bottoms of the step portions 4 in the left and right fuselage portions 2, with their rearward and vertical positions shifted, respectively. The underwater N3A shown in FIG. and a central wing support strut 6, which are arranged in a straight line in the left-right direction, and are arranged in front and above and below the hydrofoil 3B. The hydrofoil 3B shown in FIG. 4(B) has a three-point support structure, and the center support point S by the wing support strut 6
is shifted downward, forming an inverted mountain shape with a dihedral angle.

In a twin-hulled hydrofoil ship configured in this way, when the ship is at a standstill or close to this state, the hydrofoils 3A and 3B
and the step part 4 are fully submerged in the water, so they remain in a position where the buoyancy according to the displacement of each part and the weight of the ship are balanced, and most of the pair of left and right torso parts 2 are submerged in the water. This provides stability before turning the catamaran.

On the other hand, when the ship is in operation, the lifting force of both the levitation blades formed by the inclined surface 7 of the step section 4 and the levitation blades formed by the hydrofoils 3A and 3B act to lift the deck section 1 above the water surface. A pair of torso parts 2 and a part thereof float up from the water surface, and a water line is formed at a position where the buoyancy of these parts and the overall weight are balanced, for example, at the side of the torso part 2,
By reducing the volume and surface area of the submerged portion, the resistance that the body portion 2 receives due to wave resistance and viscous resistance is reduced, and the tunnel portion formed by the deck portion, the body portion 2, and the water surface. The cross-sectional area at 5 is increased, increasing the distance of the deck part 1 from the water surface, and reducing the influence of waves.

When the hull floats like this, the hydrofoils 3A and 3B are located below the step part 4 in the fuselage part 2, and the volume of the step part 4 is smaller than that of the fuselage part 2. The hydrofoils 3A and 3B do not fully rise up from the water surface, and the hydrofoils 3A and 3B remain submerged, increasing the submergence rate of the hydrofoils 3A and 3B. is not exposed above the water. Furthermore, as shown in Fig. 3, since the hydrofoils 3A and 3B are arranged so that they do not overlap vertically or horizontally, the intersection position with the water flow is shifted vertically, etc., resulting in the cavity yong phenomenon. In addition to suppressing the occurrence of N3A in water,
・Even if the cavity john phenomenon occurs partially by changing the point where 3B intersects with the water flow, the overall buoyancy force and the buoyancy force due to the individual underwater g3A and 3B will be affected by the cavity John phenomenon. It becomes stable.

In addition, Fig. 4(C) and Fig. 4(D) show underwater M3C・
Another example of 3D is shown in Figure 4 (C).
3C is a four-point support structure in which support points S are arranged on a pair of left and right step portions 4 and two wing support struts 6 between them, and are set in a straight line in the left and right direction. )
The underwater g31) shown in Fig. 31) has a four-point support structure and has a dihedral dihedral structure.

Then, each hydrofoil 3A to 3 shown in FIGS. 4(A) to 4(D)
Due to the combination of D, the shape projected from the front is shifted so that they do not overlap, that is, they are installed in a staggered manner.In this case, a technique for shifting the position of the support point S on both sides up and down may also be used. .

``Effects of the Invention J'' As explained above, the twin-hulled hydrofoil according to the present invention provides the following excellent effects.

A. Since a pair of left and right torso sections are provided at the bottom of the deck, the torso sections are submerged in water when the boat is stopped, providing stability against rolling motion.

B. Since hydrofoils are installed 7 at the bottom of the pair of parts a, the hull is lifted above the water surface, reducing the water resistance that the hull receives, and improving the ultra-high-speed operation performance of hydrofoil boats. You can make use of it.

C. By installing the hydrofoils in different steps, the intersection position of the hydrofoils and the water flow is shifted, which reduces the influence of the wing body flow between the upper and lower hydrofoils and reduces the occurrence of cavitation phenomenon. Furthermore, even when a cavitation phenomenon occurs, stable buoyancy can be obtained by preventing the bubble flow from intersecting both the upper and lower hydrofoils.

D. By changing the dihedral angle of the hydrofoil depending on the position,
It is possible to easily arrange the hydrofoils at different levels, and to suppress the occurrence of cavitation phenomena.

By providing a step section at the bottom of the E-fuselage section, the hydrofoil at the bottom is reliably submerged in the water, increasing the submersion rate during operation and stabilizing the buoyant force of the hydrofoil. , can improve athletic performance.

[Brief explanation of drawings]

1 to 4 show an embodiment of the twin-hulled hydrofoil Maran according to the present invention. FIG. 1 is a plan view, FIG. 2 is a front view, and FIG. - ■ line arrow view, Figure 4 (A
)(B)(C)(D) are model diagrams of each example of the hydrofoil portion. 1... Deck part (hull), 2... Fusel part, 3A to 3D... Hydrofoil, 4... Step part, 5... ... Tunnel section, 6 ... Wing support strut, 7 ... Inclined surface.

Claims (1)

[Scope of Claims] 1. A pair of left and right body parts are provided at the bottom of the deck part, and at the bottom of the body parts, spaced apart in the front and rear direction,
A twin-hulled hydrofoil boat, characterized in that the hydrofoils whose bottom portions are connected in the left-right direction are arranged in a staggered manner with their positions shifted in the vertical direction. 2. A step portion having a forwardly rising inclined surface is provided at the bottom of the pair of left and right body portions, and a plurality of hydrofoils are disposed at the bottom of the step portion. Twin-hulled hydrofoil. 3. The twin-hulled hydrofoil boat according to claim 1 or 2, wherein the dihedral angles of the plurality of hydrofoils are set differently depending on the front and back or top and bottom positions.